Axial Resolution
How many formulas does Axial Resolution have,
1, 2, or 3?
Three: 1 Axial Resolution (mm) = SPL(mm)/2
2 Axial Resolution (mm) = wavelength X num. of cycles in pulse/2
3 In soft tissue:
Axial Resolution = .77 X number of cycles in pulse/2
How is a short pulse created?
Less Ringing and higher frequency
What is Lateral Res.?
The ability to identify two structures that are close together when they are perpendicular to the sound beam's axis
How does Focusing improve lateral resolution?
Focusing concentrates the sound energy in a narrower beam.
What do the "A", "B" and "M" represent in each type of Display Mode?
Amplitude, Brightness, and Motion
What are the units of Axial Resolution?
mm or any other unit of distance
True or false: Longer pulses improve axial resolution
False. Shorter
What question does Lateral Res. answer?
What is the minimum distance that two structures, positioned side by, can be apart and still produce two distinct echos?
When focusing what happens to the near zone length? (Increased or reduced?)
It is reduced.
Which Display Mode looks like a city sky-line?
A-Mode.
What does axial resolution measure?
The ability of a system to display two structures that are very close together when the structures are parallel to the sound beams axis.
What is Axial Resolution related to?
Spatial Pulse Length
What are the units of Lateral Res.?
Any unit of distance: cm,mm, etc.
True or False. When Focusing the size of the focal zone is reduced
True
Which Mode appears as a line of dots of varying brightness?
B-Mode
Axial Resolution answers what question?
The minimum distance two structures, positioned parallel to the beam can be apart and still produce an accurate image
What is the numerical value range for clinical imaging?
Ranges from 0.1 to 1.0 mm.
What is Lateral Res. determined by?
Width of the sound beam.
Is phased array adjustable?
Nope
Which Mode's sampling rate is equal to the system's PRF?
M-Mode
Answer: The ability to create accurate images.
(What is the question?)
What is Resolution?
What are the synonyms for Axial Resolution?
Longitudinal, Axial, Range, Radial, Depth
What are the synonyms for lateral resolution?
Lateral, Angular, Transverse and azimuthal.
What are the three methods of Focusing?
External, internal, phased array
Which Mode is the basis for all other types of gray scale imaging?
B-Mode.